For various land vehicles, it is important that they can be leveled in parked condition (on a ground surface) and can be stabilized in the leveled position. This is the case in particular for camping vehicles, especially for mobile homes. For this purpose, several corner bracing units, each of which comprises a bracing leg that can be lowered onto the ground surface, are provided on the land vehicles in question.
Such corner bracing units are known in various structural forms. In this respect, a distinction can be made in particular as to whether a bracing leg with fixed, predetermined length (e.g. DE 7806499 U, U.S. Pat. No. 6,089,603 A, EP 163544 A, GB 2109322 A, US 2003/0001373 A1) or else a bracing leg of variable length is used. In the said latter case, the bracing legs may comprise in particular several elements capable of being displaced longitudinally (e.g. by hydraulic means) relative to one another—in the manner of a telescope—or else several members connected to one another in hinged relationship—in the manner of a scissors jack—wherein the bracing leg in question with variable length can additionally be mounted with the ability to pivot (between an operating position and a stowed position) around a substantially horizontal axis. For corner bracing units with a bracing leg that has a fixed predetermined length, the bracing leg is regularly, as indicated in the introduction, mounted with the ability to pivot around a substantially horizontal axis. In order to brace the land vehicle on the ground surface, the bracing leg is pivoted from its raised stowed position into its lowered operating position, until it is seated on the ground surface with a foot (which may be hinged) disposed at its end and the land vehicle—in combination with its further corner bracing units—is leveled and stabilized in the leveled position.
Spindle drives are widely used for pivoting the bracing legs of corner bracing units. This is the case in particular for corner bracing units of the type indicated in the introduction with a bracing leg that is inherently rigid, i.e. cannot be varied in length. In this situation, the more or less horizontally oriented spindle of the spindle drive in question can typically be turned by means of a hand crank that can be fitted onto one end of the spindle. Between a spindle nut, which is disposed on the spindle (which is subjected to tension) and the bracing leg, a swinging arm subjected to pressure then acts that is connected in hinged relationship with both parts. Otherwise, for increased comfort, comparable corner bracing units are equipped with a hydraulic cylinder-and-piston unit in such a way that the spindle is replaced respectively by a hydraulic cylinder. The hydraulic cylinders are supplied by a common, central hydraulic assembly with an electrically driven pump, wherein a central control and operating unit acts on a valve group (if necessary, automatically, using signals of position sensors) in order to pressurize the individual hydraulic cylinders separately according to need.
A land vehicle, which in addition to the features indicated in the introduction, is characterized in that each of the corner bracing units comprises at least one hydraulic cylinder-piston unit linked at its ends on the one hand to the bearing member and on the other hand to the bracing leg, is known from US 2003/0001373 A1.